state: refresh policy nodes inside the peer map build

One peer build per tag/user/IP/route write; callers detect policy moves
via NodesGeneration. Per-node caches only store results for the node
pm holds, so a mapper reading mid-build cannot pin a stale filter.

hscontrol/api/v1/auth.go

@@ -91,16 +91,18 @@ func registerAuth(api huma.API, b Backend) {
 			util.RegisterMethodCLI,
 		)
 		if err != nil {
+			b.Change(nodeChange)
+
 			return nil, mapError("registering node", err)
 		}
 
 		routeChange, err := b.State.AutoApproveRoutes(node)
+		b.Change(nodeChange, routeChange)
+
 		if err != nil {
 			return nil, huma.Error500InternalServerError("auto approving routes", err)
 		}
 
-		b.Change(nodeChange, routeChange)
-
 		out := &authRegisterOutput{}
 		out.Body.Node = nodeFromView(node)